Larger doses of nicotine cause permanent blocking of the nervous system.

An excerpt from the article 15 facts about nicotine

Nicotine binds permanently to nicotinic receptors in nerve cells, disturbing their metabolism. Initially, there is a feeling of lightness, then a change in perception, a change in the perception of the surroundings, photophobia, fatigue, lack of energy, a feeling of detachment from reality, thoughtfulness, vomiting, and diarrhea. In even higher doses, the field of vision becomes blurred and hallucinations may appear - usually black and white images. At extreme doses, loss of consciousness, convulsions, and death occur.